Manufacture of toroidal coils



v gn b- Dec. 11, 1962 c. VAZQUEZ 3,068,381

MANUFACTURE OF TOROIDAL COILS Filed May s. 1957 2 Sheets-Sheet i F357 HEB //YVNTOR ammzs's vnzausz Dec. 11, 1962 c. VAZQUEZ MANUFACTURE OF TOROIDAL COILS 2 Sheets-Sheet 2 Filed May 8. 1957 Fig.10

Fig.9

INVENTOR 014 9455 4420052 its States The present invention concerns improvements in the manufacture of toroidal coils.

Magnetic circuits in the form of a tore are already known, the low coeflicient of losses of which renders the use thereof necessary despite their higher cost, which is due to their form. One of the difliculties encountered in coiling toroidal windings resides in maintaining the tore during the coiling operation, this generally being effected by means of jaws bearing directly on the wire of a coiled winding. Despite the precautions taken, this frequently results in deteriorated or broken wires due to the contact of the gripping jaws, as a result of which it is necessary to employ wires having mechanically robust insulation. Moreover when one winding is finished and it is necessary to change the position of the tore for coiling a second winding, it is necessary successively to release the gripping jaws, to place the tore in another position and to tighten the jaws at the new position, which takes a relatively long time compared with the coiling time itself. This lost time obviously increases with the number of windings.

The whole winding thus obtained is frequently covered by a protective insulating ribbon, through which there can be passed in one region of the tore the ends of the windings, which have previously been joined to wires which are of different colours to enable them to be distinguished, and of larger diameter to impart greater mechanical strength thereto. However, despite these precautions, the finished tore is a relatively fragile product which is not very suitable for industrial use.

One of the objects of the invention is to facilitate the coiling and connection of the various toroidal windings on an annular core and to permit the use of an enamelled wire without disadvantage. Another object of the invention is to obtain a product of industrial form, the winding of which is mechanically well protected and can be readily handled and used without requiring any special precautions. A further object of the invention is to pro vide a product adapted to the printed circuit technique.

One feature of the coil according to the invention resides in the fact that it comprises an insulating carcass which is divided externally, or at its outer periphery, into coil winding compartments and encloses and protects the magnetic core, while facilitating the winding of successive coil sections co-mpartment-by-compartment, the gripping jaws of the machine bearing against outer edges of separating partitions defining the compartments.

The insulating carcass according to the invention preferably consists of two thin identical insulating half-shells which are contiguous after assembly, each half-shell being provided with a number of thin fins, of which the plane oriented along one radius is perpendicular to the plane in which the two half-shells are joined, the number of fins being equal to the number of windings. The gap between two consecutive fins corresponds to one winding compartment, in which a winding is lodged. This arrangement has various advantages. A first advantage of the fins is that they provide a means for holding the tore parts together and in desired positions during the winding operation. A second advantage is that the division into compartments provides for readily locating the leading-out wires of the windings. Finally, a further advantage of the fins is that they perform the function of a atent tooth of a ratchet wheel for a ratchet mechanism forming part of the winding machine, which mechanism is actuated after the winding of one compartment in order to advance the following compartment.

The ribs project to a considerable extent above the annular portion of the carcass and are as far as possible from the centre so as to be readily gripped in the jaws of the coiling machine without detrimentally affecting the coiling, while in addition the action of the feed pawl on the rib is facilitated by the said projecting portion without detrimentally affecting the coiling. The fact that the ribs are as far as possible from the centre imparts a large leverage to the pressing force applied to the upper jaw to maintain the tore in position during the coiling and in itself enables this force to be relatively small while having a considerable gripping couple. It is also advantageous to have a fairly weak pressing force during the movement of the carcass by means of the pawl, since the ribs are thus not likely to be damaged by friction against the jaws.

The ribs are of rounded form at the top to prevent engagement of a wire by an angular portion during the coil ing and to ensure that the V-shaped grooves of the gripping jaws are in contact with the ribs only at the point of tangency. This also permits of ensuring good constancy of the position of tore parts and readier movement of the tore in its winding assembly.

The ribs are thin and do not project into the interior of the small circle of the tore and are even substantially spaced radially outwardly from this inner circle and thus leave maximum space, especially at the centre, to facilitate the coiling.

Each annular half-shell of the carcass comprises a projecting portion around one half of its circumference and a complementary recess extending around the consecutive half of its circumference. By virture of the fact that the two half-shells are so mounted that their recessed and projecting portions fit together, the ribs are automatically located one above the other, the two half-shells being identical.

A further feature of the invention resides in a mounting by which the tore previously obtained is maintained between two insulating cheeks or cover members each provided with terminals associated either with all or with some of the leading-out wires of the windings, the height of the fins determining the spacing between the two checks.

The two terminals associated with one winding are situated level with this winding and in proximity to the outer edge of the insulating cheek. Two recesses formed in the peripheral edge of the cheek and level with the corresponding terminals permit of lodging the two leading-out wires of the winding which are directly soldered to the terminals. It is to be noted that it is the two leading-out wires of the winding itself consisting of an enamelled wire which are thus welded directly to the pins and that there is no taking up of the leading-out wires of the winding by wires of larger diameter.

Further features of the invention will become apparent from the description hereinafter given with reference to the figures of the accompanying drawings, which show by way of example various embodiments of the invention.

FIGURE 1 is a plan view as seen from the outside of an insulating half-carcass.

FIGURE 2 is a section along the line AA of the half-carcass of FIGURE 1,

FIGURE 3 is a section through the magnetic circuit with its carcass,

FIGURE 4 is a diagrammatic illustration of the winding of a tore according to the invention,

FIGURE 5 shows the outer face of a cheek,

FIGURE 6 shows the inner face of the same cheek,

FIGURE 7 is a section through the cheek along the line 3-3 of FIGURE 5,

FIGURE 8 shows a detail of the positioning of the fins in a cheek,

FIGURE 9 shows the whole assembly of the toroidal coil,

FIGURE 10 shows the two jaws of the machine gripping the tore,

FIGURE 11 shows the movement of the feed pawl, and

FIGURE 12 shows the device providing the gripping pressure for the upper jaw.

FIGURES 1 and 2 illustrate an insulating half-carcass which consists of a hollow ring ll, which is U-shaped in cross-section, and a number of thin fins or ribs 2 disposed perpendicularly to the ring and oriented along radii, the said fins defining between them coiling compartments each of which may correspond to the recess for a winding. As seen in FIGURES l and 2, the fins 2 are at least as thin as the thickness of the annular portion of the insulating material of the shell l. The figure illustrates a tore comprising six windings, but it is obvious that the invention is applicable to any number of windings and that the compartments need not be disposed regularly around the ring. it will be noted that the fins preferably have a rounded form 3, whereby they are prevented from becoming engaged with the wire during the coiling, the latter taking place compartment-by-compartment, and the plane formed by the storage device for the wire to be coiled being fixed, while the ring moves through this plane with a reciprocating movement between two positions corresponding to the spacing between two consecutive fins. One of the arms of the U-shaped cross-section of the ring comprises around half of the ring circumference a portion 4a projecting from the junction plane 5 and around the other half of its circumference, in prolongation of the first, a portion 4b which is set back from the junction plane.

A magnetic circuit ready for coiling in accordance with FIGURE 3 is formed by disposing a magnetic core 6, which may be formed by a number of stacked laminations, or by a metal tape wound in ring form, or by compressed powders, or by any other method, in the U-shaped cavity of an insulating half-carcass. The core projects from the U-shaped cavity by half its thickness and there is then fitted over the projecting portion of the core a second insulating half-carcass so that the portions 4a and 4b of one half-carcass mate with the portions 4b and 4a respectively of the opposite half-carcass. It is possible to stick the two half-carcasses together in such manner as to form a rigid assembly. The winding of this assembly is effected in accordance with FIGURE 4, in which the six windings are numbered I to VI. Preferably, but not necessarily, the windings are so designed that the same winding wire is used for each of them, whereby changing of the wire supply reel during winding is avoided.

When the assembly to be wound has been disposed between the gripping jaws mounted on the machine and bearing on the edges of a number of ribs, the coiling of the first winding I is commenced, starting with the free end a of the wire to be coiled. When the number of turns forming the first winding has been completed, a loop b is formed with the winding wire and the coiling of the second winding II is commenced after the tore has been turned through the angle corresponding to the coiling which has just been completed. The rotation for the new positioning is effected by a ratchet mechanism, one tooth of the ratchet wheel of which is represented by a rib, the advance being effected after the coiling of each compartrnent. When the second winding has the required number of turns, a loop 0 similar to the preceding loop b is formed and the coiling of the third winding is commenced. This is continued until the sixth winding after the formation of the loops a, e and f and the free end g is finally led-out. The coiled tore therefore has five loops b, c, d, e and f, and the two free ends a and g. It is then :5. placed between two insulating cheeks corresponding to FIGURES 5, 6 and 7.

The external diameter of the cheek corresponds to the overall dimensions of the wound tore, including the ribs. The two leading-out wires of one winding are connected to two pins such as 7, and enter two protective recesses 8 situated opposite the pins. Each cheek comprises only three pairs of pins, but each wound tore utilizing two cheeks comprises the six pairs of pins necessary for the connection of the six windings.

FIGURE 6 shows the inner face of a check. Two ribs are keyed in the slots 9, the width of which corresponds exactly to the thickness of a rib and which comprises (see FIGURE 8) slopes 511 corresponding to the slope of a rib, two opposite ribs beint thus completely supported, while the other recesses it which are wider than the thickness of a rib, permit a certain freedom of movement to take account of the manufacturing tolerances in the positioning of the ribs.

FEGURE 7 is a sectional view of the cheek along the line 23- 3 of FIGURE 5. A hole llIl serves for the passage of a screw, of which the head, or lock nut, is lodged in a hexagonal recess 12. It is to be noted that a flange E3 is provided, which projects to an amount corresponding to the lower portions of the pins '7 on which are wound the leading-out wires of the windings, so that the upper portions of the pins 7 are free and smooth and permit plugging-in. The check comprises in its lower portion a flange forming an insulating passage for the screw by which the two cheeks are held in position.

The arrangement illustrated in FIGURE 9 is assembled as follows: A coiled tore is disposed on the inner face of a cheek bearing no locating impression 15, the ribs being lodged in the slots 9 and 10. The second cheek bearing a locating impression 15 is then so positioned that the said locating impression is positioned at the centre of the compartment in which the two leading-out wires a and g are situated. The six pairs of pins correspond to the leading-out wires of six windings, and three pairs of pins associated with each cheek are disposed quincuncially with respect to the three pairs of pins associated with the other check, that is to say, there always correspond to each coiling compartment two pins only, and for the successive windings the two pins are situated alternately on one check and on the other. The checks are maintained in this position by means of a screw 16 fitted through the two cheeks and through the tore and screwed in a nut 17 disposed in the hexagonal recess 12 in the cheek.

The leading-out wires of the different winds are then connected. Referring to FIGURES 4 and 5, the free end a of the wire is connected to the terminal 7 situated to the right of the locating impression 15 and corresponding exactly to the terminal marked E in FIGURE 4. The loop b is cut and the portion b of the loop is connected to the other pin 7 situated to the left of the locating impression 15 and corresponding exactly to the terminal marked 8; in FIGURE 4. In FIGURE 9, it will be clearly seen how the end a passes through the recess corresponding to the pin E and is connected to the latter, and the end I); passes through the recess corresponding to the pin S and is connected to the latter. It will be seen in FIGURE 4 that the end 12 is connected to the pin E and that when the loop 0 has been cut the end 0 is connected to the pin S It will be seen in FIGURE 9 that the end [2 passes recess corresponding to the pin E and is connected to the latter, and the end 0 passes into the recess corresponding to the pin S and is connected to the latter. The connection is thus continued in a similar manner for the other windings. When the wires have been connected to each outer face of the cheeks the welding is effected simultaneously for all the wires of the same face by immersion in a tin bath, the enamelled wire of the winding welding automatically without any previous scrap ing of the connections.

The coiling machine comprises, as stated, special devices for maintaining the tore during its winding and utilising the ribs to effect the change of the compartment to be wound.

The principle of these devices is illustrated in FIG- URES 10, l1 and 12. In FIGURE 10, the tore 18 to be wound is disposed between a fixed lower jaw 19 and an upper jaw 20 bearing with some pressure in the direction of the arrow A on the edge of the ribs of the carcass. It will be noted that the two gripping jaws comprise a V-groove 21, each arm of the V bearing tangentially against the rounded portion of a rib. The lower jaw has, over a portion of its length, a central groove 22, in which there is adapted to slide a pawl 23 as shown in FIG- URE 11. The pawl 23 has a profile such that in its circularmovement centred on the shaft 24 it yields on encountering a rib 25 when it is moved in the direction of the arrow f while on the other hand it drives the rib in its movement when it is actuated in the direction of the arrow f The yielding movement of the pawl 23 takes place from the top downwards in the direction of the arrow 2; (see FIGURE The pawl returns into its uppermost position under the action of a spring as soon as it is no longer impeded by the rib. The two pawls 23 are'operated by a lever 26 adapted to be brought into their initial position by a return spring 27.

. In FIGURE 12, it will be seen that the upper gripping jaw 20is mounted on the end of an arm '28, to which is secured a pin 29 adapted to turn in a fixed member 30. A spring 31 bearing on the one hand against the flange 32 of the member 30 and on the other hand against the annulus 33 fixed on the pin 29 tends to push the pin in the direction of the arrow f and therefore to apply the jaw 20 against the member 18 to be wound. The movement in the direction of the arrow f is limited by an abutment 34 fixed to the fixed member 32. In addition, the coil spring 31, which also acts with fiexure, tends to impart to the arm 28 a circular movement in the direction of the arrow f which movement is limited by abutments such as 34, which therefore serve a double purpose. The device illustrated in FIGURE 12 functions as follows: The tore to be wound having been disposed on the lower jaw 19, a pressure is exerted from the bottom upwards under the member 33 which, being urged by the torsion spring 31 and disengaged from its abutments 34, rotates. The jaw 20 takes up a position above the tore 18 to be wound, and when the pressure under the member 33 ceases, the jaw 20 abuts the ribs of the carcass to be wound.

After each Winding, the carcass is operated by the lever 26, which permits of changing the winding compartment. When all the compartments have been wound, the tore is disengaged by again applying pressure under the member 33 to lift the jaw 20.

It will be obvious that further modifications of the insulating carcass comprising ribs are possible. For example, the carcass may be directly moulded on the magnetic core, or carcasses may be employed in Which the number of ribs and the form thereof are different, or again a modification as possible, in which the cheeks for maintaining the wound tore comprise connecting pins of a different design, and a dilferent device may be employed for keying the ribs, for example by means of projections on the cheek rather than slots, or a modified form may be employed in which the device for maintaining the checks on the wound tore are different, but all these modifications proceed from the same basic ideas and therefore obviously do not depart from the scope of the invention.

The present invention is applicable to all branches of the electrical industry in which toroidal cores are manufactured, regardless of the dimensions thereof. It is applicable more especially in cases where the small dimensions of the tores and the fineness of the wires of the windings render the various winding and assembly operations more delicate.

6 I claim:

1. A toroidal coil structure comprising a magnetic circuit surrounded by an annular insulating carcass, the carcass being constituted by a plurality of shell portions mounted contiguously on the magnetic circuit, and being provided with outwardly projecting ribs defining coil winding compartments on said carcass, coil windings in said compartments, said ribs extending beyond the outer periphery of said windings, and cover means engaging the outwardly projecting portions of said ribs on opposite sides of the coil windings and magnetic circuit, said cover means having on its outer face terminal means for making electrical connections to each of the coil windings.

2. A coil according to claim 1, wherein the ribs are disposed entirely radially outwardly of and in substantially spaced relationship to the small circle defined by the inner diameter of the carcass.

3. A coil according to claim 1, wherein the ribs have a triangular form, the top of each of which is rounded and extends above the plane of said junction and is remotely located from the center of the coil.

4. A coil according to claim 1, wherein said ribs are uniformly spaced around said coil.

5. A toroidal coil comprising a magnetic circuit surrounded by an annular insulating carcass, the insulating carcass being constituted by two identical half shells having hollow annular portions mounted contiguously on the magnetic circuit and each half shell being provided with ribs each of which is in a generally radially extending plane perpendicular to the plane of the junction of th two half shells so as to define coil winding compartments, coil windings encircling said carcass and said magnetic circuit in said compartments, each of said ribs being disposed so as to project only above and radially outwardly from the annular portion of the respective shell leaving thereby maximum space at the center of said annular carcass for said windings, and the carcass also including in its annular area a projecting portion around one portion of its circumference and a recess extending around the diametrically opposite portion of its circumference so that the recessed and projecting portions of the two identical half shells, by fitting one into the other, lock the ribs one above the other.

6. A toroidal coil comprising a magnetic circuit surrounded by an annular insulating carcass, the insulating carcass being constituted by two identical half shells having hollow annular portions mounted contiguously on the magnetic circuit and each half shell being provided with ribs each of which is in a generally radially extending plane perpendicular to the plane of the junction of the two helf shells so as to define coil winding compartments, coil windings encircling said carcass and said magnetic circuit in said compartments, each of said ribs being disposed so as to project only above and radially outwardly from the annular portion of the respective shell leaving thereby maximum space at the center of said annular carcass for said windings and the two half shells being applied one against the other in such manner that the ribs take up a position one above the other, and an insulating cover having on its outer face a number of pairs of pins at least equal to one half of the number of windings, each pair of pins being associated with a respective coil winding, and a recess being formed level with each pin in the edge of the cover at its outer periphery to accommodate a terminal portion of a respective winding extending to the respective pin.

7. A toroidal coil comprising a magnetic circuit surrounded by an annular insulating carcass, the insulating carcass being constituted by two identical half shells having hollow annular portions mounted contiguously on the magnetic circuit and each half shell being provided with ribs each of which is in a generally radially extending plane perpendicular to the plane of the junction of the two half shells so as to define coil winding compartments,

coil windings encircling said carcass and said magnetic circuit in said compartments, each of said ribs being disposed so as to project only above and radially outwardly from the annular portion of the respective shell leaving thereby maximum space at the center of said annular carcass for said windings and the two half shells being applied one against the other in such manner that the ribs take up a position one above the other, an insulating cover bearing terminal pins for at least part of said windings on an outer face thereof which is generally parallel to said plane, said cover also having impressions on its inner face to receive and provide centering of the ribs of the carcass so that the two terminal pins associated with each respective winding are disposed in predetermined relationship to said winding.

8. A toroidal coil comprising a magnetic circuit sur-- rounded by an annular insulating carcass, the insulating carcass being constituted by two identical half shells having hollow annular portions mounted contiguously on the magnetic circuit and each half shell being provided with ribs each of which is in a generally radially extending plane perpendicular to the plane of the junction of the two half shells so as to define coil winding compartments, coil windings encircling said carcass and said magnetic circuit in said compartments, each of said ribs being disposed so as to project only above and radially outwardly from the annular portion of the respective shell leaving thereby maximum space at the center of said annular carcass for said windings and the two half shells being applied one against the other in such a manner that the ribs take up a position one above the other, said windings being disposed between two identical covers which carry terminal pins for the windings, the covers being oriented in such a manner with respect to one another that groups of pins associated with successive windings of the coil are disposed alternately on one cover and the other.

9. A coil according to claim 8, comprising recesses for the protection of winding leading-out wires in the outer edge of each cover, the two leading-out wires of each winding passing through a respective recess and being connected to two pins disposed level with this winding.

10. A coil according to claim 9, wherein the two covers are maintained against the coil structure by a centering screw and a nut, the head of the screw bearing on one of the covers, and including a recess adapted to the nut in the opposite cover for receiving the not which is threaded on the screw.

References Cited in the file of this patent UNITED STATES PATENTS 

